Asymmetrical support strip chassis sealants

ABSTRACT

The aim of the invention is the development of a support strip, which lends a seal, made from a rubber material, a stiffness adequate for production and assembly, has good extension and compression properties, has an adequate mobility in order to be able to follow the given directional curves of the chassis components and lends the seal a clamping force sufficient for a secure and durable seating of the seal on the attachment flange of the chassis components. Said aim must be achieved with the proviso of a lowest possible weight and low production costs for said support strip. The aim is achieved by means of an asymmetric arrangement of short ( 2 ) and long ( 3 ) wedge-like recesses and slots ( 4 ) in the support strip as in FIG.  1 , permitting a low weight and low production costs in fulfilling the said aims. The invention further relates to an asymmetric strip which can be used as reinforcing support for a seal made from rubber material in chassis production of automobiles.

This application claims the benefit of German Application No. 101 01778.2 filed Jan. 17, 2001 and PCT/DE01/04685 filed Dec. 12, 2001.

BACKGROUND OF THE INVENTION

The present invention concerns an asymmetrical, metal strip which isused to hold a gasket made of rubber-like material for auto bodies. Whenthe metal-backed gaskets are installed, they are fastened to therelevant flanges on the car body, here in particular to the trunk lidand the doors.

The metal mounting strip ensures a sufficient adhesion to thearbor-mounted flange, and thus a secure and enduring seat for thegasket, which could not be achieved with a gasket of rubber-likematerial alone.

A mounting strip is manufactured by stamping out notches and slots froma metal strip as an intermediate product, bent into a U-shaped crosssection and subsequently sprayed with a rubber-like, pliable gasketmaterial.

The basic demands on such a mounting strip when used as a component of agasket in the automobile body region are to be seen in the followingpoints:

Good performance under tension and compression,

High tensile strength,

High mobility in all directions,

High adhesive strength,

Low weight as well as

Low manufacturing costs.

Good performance under tension and compression is especially requiredwhen the gasket is ready to be installed in the car; in particular, ifthe gasket can stretch or be compressed without forming creases, and ifthe assembler can compensate for slight discrepancies in length whichoccur during the manufacture of the gasket strip. This will relax thedemand for the high tolerances in the manufacturing process, whichreduces the costs of the process.

The demand for the highest tensile strength possible, is based upon thefact that the gasket strand is exposed to a tensile stress duringmanufacture, and should not tear in the process.

A gasket should be flexible in all directions, so that during assembly,the assembler can follow the specified procedure for arbor-mounting tothe automobile body.

A high adhesive strength between gasket and the arbor-mounted flange onthe body brings about a secure and durable fit of the gasket on thearbor-mounted flanges on that part of the body.

In order to save on production costs and fuel costs for operating theautomobile, the weight of the gasket should be kept as low as possible.For this reason, aluminum is frequently used as a support material,which nonetheless has negative effects on the physical properties of themounting strip, and therefore the thickness of the material must oftenbe increased.

Moreover, the configuration of the mounting strip should enable the mosteconomical manufacture possible.

DE 19725166 A1 contains information about a metal strip, which besideslengthwise notches, also has corrugation-like stamped creases. Thanks tothe notches, the strip can be stretched and compressed. The stampingsensure a high adhesive strength of the gasket to the relevant bodyparts, and therefore allow for a reduction in the thickness and weightof the material. In the subsequent processing of the strip, thedisadvantages of the stampings nonetheless become apparent, in that aspecial bending tool is required for bending the strip into the U-shapedcross section, so that the shape of the stamping at least not totallylost in the process. Furthermore, the stamping process requiresadditional tools. The finished strips are wound into spools forsubsequent processing or for transport; but the stamping process leadsto a greater effective strip thickness and hence a greater volume of thespool. In addition, problems arise when the metal strip is sprayed withthe rubber-like gasket material.

DE 69501998 T2 and DE 3628448 C2 describe metallic strips which aremanufactured according to the roll cutting process. Here the notches arenot stamped out, but are cut using a tool in the shape of a thin line.

The notches notch get their characteristic shape through a subsequentstretching. With this manufacturing method, however, it is possible tocreate only symmetrical notches. The form that the notches take is thusquite inflexible, and is not easily brought to the desired thicknesscriterion. Consequently, when strips are manufactured according to theroll cutting process, owing to the consequent notch effect, a greatermaterial thickness is required in order to achieve the same strength asthose of a strip which was produced using the stamping process.

Furthermore, DE 3628448 C2 contains information on a strip whose bendingbehavior is said to be improved by an asymmetrical arrangement of thenotches. This is attained by making short notches inside the bend, andlong ones on the outside. This nonetheless leads to problems if a gasketstrand is supposed to follow various different directions along a bodypart.

SUMMARY OF THE INVENTION

With this as a starting point, the objective underlying the invention,is to develop a metal mounting strip, which imparts a sufficientstrength to the gasket of a rubber-like material for manufacture andinstallation, behaves well under tension and compression, possessessufficient mobility to follow prescribed changes in direction of variousbody parts, and gives the gasket an adhesive strength, which wouldensure a secure and enduring seating of the gasket on the arbor-mountedflange of the relevant body part. The mounting strip must fulfill theseobjectives in the context of the least possible weight as well as lowmanufacturing costs.

The objective is accomplished through a selection of the arrangement andshape of notches and slots in the mounting strip in accordance with theCharacterizing Section of claim 1 and FIG. 1, which in meeting thedemands for sufficient strength, mobility, good stretching andcompressive behavior and high adhesive strength, permits a the metalbase material to be only about 0.5 mm thick, with a correspondinglylowest possible weight, as well as low manufacturing costs with a simplemanufacturing method, namely stamping.

A prototype of the invention is given FIGS. 1 and 2, and is describedbelow with reference to the Figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a mounting strip before the bending process.

FIG. 2 shows the cited mounting strip after the bending process.

FIG. 1 depicts a mounting strip before the bending process. Short andlong wedge-shaped notches 2 and 3 as well as slots 4 are stamped in themetal base element 1. In any given case, a short and a long,wedge-shaped notch lie opposite each other, whereby the tips 2.1 and 3.1point toward each other and toward the center line 5 of the mountingstrips, and the short sides 2.2 and 3.2 of the wedge-shaped notches aredirected toward the respective edge 8 of the mounting strip. The tip ofthe long, wedge-shaped notch projects over the center line of themounting strip. The center lines of the two opposed short and long,wedge-shaped notches are coincident. In relation to the longitudinalaxis of the mounting strip, a short and a long wedge-shaped notchalternate at all times, separated in any given case by a slot. Thecenter lines of two opposed slots are coincident. The tips 4.1 ofopposed slots point toward one another and possess the same distance tothe center line of the strip. Conditioned by the described shape of thewedge-shaped notches and slots, bars 6.1 and 6.2 remain opposite to oneanother, between the tips of the short and long wedge-shaped notcheslying opposite one another as well as between the tips of slots in themetal lying opposite one another. If one connects the midpoints of thesebars, there results a zigzag like line 7 over the long axis of themounting strip.

FIG. 2 shows the cited mounting strip after the bending process, in thecourse of which a U-shaped cross section was created.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Thanks to the wedge-shaped form of the notches, and by theirasymmetrical arrangement of the short and long, wedge-shaped notches, agreat capacity for stretching and compression, in combination with agreat strength and adhesive force of the gasket is attained. In theprocess, what is attained in the region of the long, wedge-shaped Notch3, is a great stretching and compressive capacity as well as a mobilityof the mounting strip in all directions, while the short, wedge-shapednotch 2 brings about that the metallic bar between tips 2.1 and 3.1 ofthe opposed short and long, wedge-shaped notches, has a sufficient widthto achieve great stability and strong adhesion of the gasket. Highmobility of mounting strip is also attained in that the tip 3.1 of thelong wedge-shaped notch reaches over the center line of mounting strip5.

In this way, that the connection of the midpoints of bars 6.1 and 6.2forms a zigzag-shaped line, and the stretching and compressive behaviorof the mounting strip and its flexibility are additionally increased,and the formation of creases upon compression is counteracted since acontinuous, straight metallic bar is avoided.

In this connection, a length ratio of short to long wedge-shaped notchesof about 1 to 2 has proven to be especially advantageous.

REFERENCE NUMBER LIST

1 Metal base element

2 Short, wedge-shaped notch

2.1 Tip of the short, wedge-shaped notch

2.2 Short side of the short, wedge-shaped notch

3 Long, wedge-shaped notch

3.1 Tip of the long, wedge-shaped notch

3.2 Short side of the long, wedge-shaped notch

4 Slot

4.1 Tip of the slot

5 Center line of the mounting strip

6.1 Metallic bar between 2.1 and 3.1

6.2 Metallic bar between the tips of two opposed slots

7 Connection line of the midpoints of the metallic bars 6.1 and 6.2

8 Edge of the mounting strip.

What is claimed is:
 1. Mounting strip for automobile body gaskets withasymmetrically arranged notches and symmetrically arranged slots,wherein the notches are constructed wedge-shaped, in that in each case ashort and a long wedge-shaped notch whose center lines are coincidentlie opposite each other, the tips of which point toward each other andtoward the center line of the mounting strip and the short sides ofwhich are directed toward the respective edge of the mounting strip, inthat the long, wedge-shaped notch projects over the center line of themounting strip, in that in relation to the long axis of the mountingstrip in any given case a short and a long wedge-shaped notch alternate,at all times separated by a slot, in that the connection of themidpoints of the bars forms a zigzag-shaped line between the short andlong, wedge-shaped notches and between the tips of the slots.
 2. Themounting strip of claim 1 for automobile body gaskets withasymmetrically arranged notches and symmetrically arranged slots,wherein the length ratio of the short to the long wedge-shaped notchcomes to about 1 to 2 .